SDS100/SDS200: Looking for guidance using a SDS100 to map a NXDN/IDAS system

[Facsimile]

Radio system in question: WQZE850
Control frequencies: 451.325 & 452.1875

Hello. I am trying to map out a undocumented system in the RR database. Setting the frequency to monitor 451.325 on the SDS100 enabled listening to voice but with some conversations starting in the middle of sentences. The indicator on the top of the display switched back and forth between NEX4 and IDAS depending on who is transmitting. I attempted to add the system to the radio using Sentinel. For System Type, I chose NXDN Trunk for no reason other than it was the first NXDN option. For Site, I entered both control frequencies above into a single Site. I then tried using the LCN finder for approximately 3 hours with nothing found. No audio was heard either while Searching ID and this is a very active system. Once switching back to conventional listening, voice was audible again. I figured I could probably try NXDN One Frequency next but I really have no idea what I'm doing. It has kind of just been trial and error. Is there a better way to find what I am looking for? Let me know if I have left out any vital information that would help crack this case. Thanks!

 

[Whiskey3JMC]

The license you linked indicates Radio service IG which means the frequencies are used conventionally (non-trunked). LCNs need not apply in this case. Program them as conventional objects with correct RAN(s)

 

[Facsimile]

The license you linked indicates Radio service IG which means the frequencies are used conventionally (non-trunked). LCNs need not apply in this case. Program them as conventional objects with correct RAN(s)

Thanks for pointing that out - I never thought to look the class. When you say program them as conventional objects, do you mean set the System Type as "Conventional?" And how do I program the RANs? Is that equivalent to LCN in Sentinel?

My assumption of the term conventional was that it always meant analog, but I'm starting to get the feeling that is not the case.

 

[Randyk4661]

Ran's are like the PL tones, NAC codes

 

[RandyKuff]

 

[RandyKuff]

Facsimile​

Did you purchase the NXDN key for SDS100?

 

[Whiskey3JMC]

Did you purchase the NXDN key for SDS100?

If the OP didn't then they wouldn't be seeing the NEX4, IDAS, etc flashing on the screen

 

[tvengr]

Thanks for pointing that out - I never thought to look the class. When you say program them as conventional objects, do you mean set the System Type as "Conventional?" And how do I program the RANs?

Frequency is entered as conventional. Go to Set Audio Type. Press E. Set to Digital Only. Press E. Digital Code Option will be displayed. Scroll to Search. Press E. Press AVOID to exit the menus. When a transmission is received, , the RAN will be displayed. Once the RAN is determined, you can go back to Set Audio Type as Digital Only and scroll to Set Nexedge RAN instead of Search and Press E. Scroll to the proper RAN and press E. Press AVOID to exit menu.

 

[Facsimile]

Ran's are like the PL tones, NAC codes

Frequency is entered as conventional. Go to Set Audio Type. Press E. Set to Digital Only. Press E. Digital Code Option will be displayed. Scroll to Search. Press E. Press AVOID to exit the menus. When a transmission is received, , the RAN will be displayed. Once the RAN is determined, you can go back to Set Audio Type as Digital Only and scroll to Set Nexedge RAN instead of Search and Press E. Scroll to the proper RAN and press E. Press AVOID to exit menu.

Wow thank you for all the info! I will give conventional a try and report back. Is it fair to say that the only two frequencies that I need to have scanning are the Station Classes listed as FB2? Would there be any reason to include the MO class frequencies? Since there are two FB2 frequencies listed, is it ok to assume two channels are used (or at least two are repeated)? Or would you have to add all the FB2 and MO classes together to get the total theoretical number of channels?


One additional question - I came across THIS POST that discusses "NXDN One Frequency" versus conventional - It seems like the system is listed as IG Conventional but the recommendation is to use NXDN One Frequency. I don't understand why? Can someone clairify?

• What exactly is NXDN One Frequency?
• Is it only for trunked systems?
• How would I know when to use it over conventional?

Thanks!

 

[Whiskey3JMC]

What exactly is NXDN One Frequency?

• Is it only for trunked systems?

No. One principal difference betwen NXDN OFT & conventional is that with the former you can set digital threshold levels

 

[hiegtx]

Wow thank you for all the info! I will give conventional a try and report back. Is it fair to say that the only two frequencies that I need to have scanning are the Station Classes listed as FB2? Would there be any reason to include the MO class frequencies? Since there are two FB2 frequencies listed, is it ok to assume two channels are used (or at least two are repeated)? Or would you have to add all the FB2 and MO classes together to get the total theoretical number of channels?


One additional question - I came across THIS POST that discusses "NXDN One Frequency" versus conventional - It seems like the system is listed as IG Conventional but the recommendation is to use NXDN One Frequency. I don't understand why? Can someone clairify?

• What exactly is NXDN One Frequency?
• Is it only for trunked systems?
• How would I know when to use it over conventional?

Thanks!

In the Uniden scanners, with the NXDN upgrade, you can program the frequency one of two ways.
If you program it as a conventional channel, you can use the RAN or Area code when programming, but there is no way to enter a talkgroup, which would be desirable if the same frequency was used for several different purposes.

But if you program it as a NXDN One Frequency Trunked system, you enter the frequency as if it is a site. Then, you can create a Department which lets you specify which talkgroups you want to monitor. And, as Whiskey3 mentioned, you can specify a digital threshold, which might help you better receive the channel.

 

[Facsimile]

No. One principal difference betwen NXDN OFT & conventional is that with the former you can set digital threshold levels

What does OFT stand for?

In the Uniden scanners, with the NXDN upgrade, you can program the frequency one of two ways.
If you program it as a conventional channel, you can use the RAN or Area code when programming, but there is no way to enter a talkgroup, which would be desirable if the same frequency was used for several different purposes.

But if you program it as a NXDN One Frequency Trunked system, you enter the frequency as if it is a site. Then, you can create a Department which lets you specify which talkgroups you want to monitor. And, as Whiskey3 mentioned, you can specify a digital threshold, which might help you better receive the channel.

How do I specify a digital threshold? I wasn't able to find anything in the Easier to Read manual.


I do have the conventional results that I would like to share:


Channel number was retrieved by verbal confirmation from the radio operators. The RANs elude me. I guess I was expecting the RAN for the input to be the same as the output of the associated repeater. I checked multiple times but it was not the case as seen above. It is completely possible that they aren't inputs at all - it just appeared to be that which is why I have it listed as such. I also noticed that on Channel 3 and ?, every so often there would be different RANs associated with the frequency/channel.

I tried entering both "repeater" frequencies into a different favorite list but this time as a NXDN One Frequency. This had a lot less transmissions and most were only one sided. However when watching the screen, different unit names would appear like CENTRAL, OPS, SRVCS, etc. I assume these are programmed at the system? Many times it would take the radio 5-10 seconds before it would show these names. Other times there wasn't one listed. It was kind of nice seeing them automatically showing up - I didn't know it would do that or how it does it. Is that a trade-off? I assume you can't get the SDS100 to display unit names automatically in conventional mode?

Where should I go from here? I'd like to complete this system and enter it into the database.

 

[Whiskey3JMC]

What does OFT stand for?

One Frequency Trunking

How do I specify a digital threshold?

Nevermind, this doesn't apply to the SDS series, only to the x36HPs

 

[hiegtx]

How do I specify a digital threshold? I wasn't able to find anything in the Easier to Read manual.

I stand corrected. While you can adjust digital thresholds on the 436HP & 536HP, that is not an available option on the SDS series scanners.

On the x36HP models, that is set for each site for trunked systems, or under the Options for a Conventional system.

Since you are using an SDS100, there is no threshold that can be changed.

 

[gh6406]

What does OFT stand for?


How do I specify a digital threshold? I wasn't able to find anything in the Easier to Read manual.


I do have the conventional results that I would like to share:
View attachment 145296

Channel number was retrieved by verbal confirmation from the radio operators. The RANs elude me. I guess I was expecting the RAN for the input to be the same as the output of the associated repeater. I checked multiple times but it was not the case as seen above. It is completely possible that they aren't inputs at all - it just appeared to be that which is why I have it listed as such. I also noticed that on Channel 3 and ?, every so often there would be different RANs associated with the frequency/channel.

I tried entering both "repeater" frequencies into a different favorite list but this time as a NXDN One Frequency. This had a lot less transmissions and most were only one sided. However when watching the screen, different unit names would appear like CENTRAL, OPS, SRVCS, etc. I assume these are programmed at the system? Many times it would take the radio 5-10 seconds before it would show these names. Other times there wasn't one listed. It was kind of nice seeing them automatically showing up - I didn't know it would do that or how it does it. Is that a trade-off? I assume you can't get the SDS100 to display unit names automatically in conventional mode?

Where should I go from here? I'd like to complete this system and enter it into the database.

Facsimile, Your Channel 2 Repeater INPUT goes with your Channel 1 Repeater OUTPUT, so the Ran numbers on input and output will be the same. On UHF Frequencies, the Repeater INPUT is almost always 5 MHz higher than the OUTPUTS. Hope this helps.

 

[tvengr]

On UHF Frequencies, the Repeater INPUT is almost always 5 MHz higher than the OUTPUTS.

Except for UHF T-Band where the input frequency is 3 MHz higher than the output frequency. TV channels are 6 MHz wide. The input frequencies occupy the upper half of the channel. The output frequencies occupy the lower half of the channel.